Linear polycarbonate-containing spinning solutions



United States Patent 3,385,814 LENEAR POLYCARBONATE-CONTAINING SPKNNING SOLUTIONS Bela von Fallrai, Artur Prietzschk, Wolfgang Rellens- "ice crystallinity are capable of being produced from polycarbonate, more especially those derived from di-(monohydroxy aryl) alkanes, -sulphones, -sulphoxides, -sulphides or -ethers or a mixture of these dihydroxy commann, AlfredReichle, and Horst Wieden, Dormagen, 5 Pounds With one another, y adding to the P y Germany, assignors to Farbenfabriken Bayer Aktiengea Solutions, Prior to the Shaping thereof, InonohydroXy, sellschaft, Lever kusen, Germany, a German corporation dihydroxy and/ or higher polyhydroxy compounds or their No DFaWlng- Flletl Man 1964, 356,052 esters and ethers of the general formula Claims priority, application Germany, Apr. 11, 1963,

,4 9 1O 11-0-11 5 Claims (CL 260' 31'4) (in which R represents alkyl, aryl or aralkyl and R' represents [CH CH O] X, in which n=1 to ABSTRACT OF T E DISCLOSURE and alkyl, aryl, aralkyl or acyl), in a quantity of 10 to 100% and advantageously 25 to 50%, calculated p d solutions based a the m l n of m 15 on the quantity of dissolved polycarbonate. Particularly y y, d1hydrony r higher polyhydr xy C suitable as additives are for example diethyleneglycol pounds and esters and ethers thereof in a solvent solumonomethylether, ethyleneglycol monomethylether acetion of a polycarbonate prior to use of the same as spinrate and triethyler eglycol dimethylether, mug solutions. Films which are produced 'by casting from solutions with the said additives do not show a spherolithic struc- I i known to be ibl to produce structurgs, Which ture in polarised light when examined under the light of can be better crystallised, by adding non-solvents or poor 3 mlcrescoper mefely double-retracting elements solvents to solutions of high polymers which do not crys- Yvhlch cannot be recognised p lly a d Which lll i f il indicate a very fine miorocrystalline morphology. In ad- For example, it is possible, by adding carbon tetradltlonr the Xfay diagram and the density Point to a Wellchloride, benzene, methylpropylketone or di-n-butylether, crystallised Structure of the unstfetehed f ilto polycarbonate solutions to prepare foils of good crys- Depending on the nature of the additive, good results tallinity, and these foils, after stretching, have better are pabtlcblal'ly tonnd With additions f 20 to 40%, technological properties than the non-crystalline material, based on the q y by Weight of the Polycarbonate, whereas filaments spun from these solutions by the dry- 0 to a 13 to 25% Solution, more especially t0 spinning or wet-spinning processes only provide a ll With the transference of these results to the producincrease in the crystallinity under extreme spinning conn of fibres by the dry Wet spinning Processes, the ditions. For example, at relatively low spinning temperaeddltlon of larger quantities of 25 to s d 0 tures, a crystallisation is certainly produced, but this is the q y by Weight of Polycarbonate, P to be so irregular that the still soft, unfinished filaments likeexpedient, and the concentration of the Polycarbonate ise become very irregular when being drawm Thesg SOllltlOil should be between 14 and 23%, more especially filaments are consequently unsuitable for a further processto In order to guarantee the stability of the spinning solu- In addition, whereas the added components in a quantlon, additives Preferably are admixed continuously, i f an average 50 to 100% based on the polycar. only immediately before the shaping of the solution. bonate used, are sufficient for a good crystallisation when Due to their increased cfystallinlty, the filaments P producing foils, the aforementioned non-solvents only duced y the Process of the lnyentlon have improved h a comparatively l ffi h producing fil resistance to solvents, improved temperature stability mgnts gven h h are dd d i a hi h eXCess i and a low sensitivity to temperature during the stretching, f above 100% or almost up to h lli li i whereby in particular a better uniformity of the titre of This different behaviour of the solution during the the Stretched filaments is obtained. processing in one case to form films and in another case The following table indicates the interference Width, to form filaments is based on the differential evaporation the denelty as a Standard the Crystalllnlty of filInS and of the olvent, which proceeds ery much more lowly filaments and filSO U116 percentage II'lQSS flllCillQtlOIlS along when producing films than when forming filaments, A the filament as a standard of the uniformity of filaments,- more l t crystallisation f th polymer i th which have been produced from polycarbonate solutions fore guaranteed, this being known to be dependent on without added component and with an additive, which has i scarcely any effectiveness, and also when using a added It has now been found that filaments or films with high component Produced according to the invention- TABLE S l tion Additive X-ray Filament Resistance No. Structure concentrainterference Density uniformity, to trichloron, Type Quantity, Width, percent 3 ethylene percent percent percent degree 1 18 Without 2.8 1.1970 Unstable. 18 Benzene 2. 6 1.1980 Do. 18 Carbon tetrachloride 2. 45 1. 1980 Do. 17.5 Methylglycol acetate" 1.40 1.2130 Stable. 18 Diethyleneglycol monethylether. 1 50 1 2119 Do. 18 Without 1. 8 1. 1970 Unstable. 17 Benzene. 2. 1.1975 Do, 17. 5 Methylglycol acetate 42 1. 32 1. 2140 Stable. 17 Diethylencglycol monoethylethe 28 1.4 1.2160 Do.

1 The interference width," as used herein, means the width of the main maximum of the X-ray dispersion curve of polycarbonate recorded with C11 K-radiation. It is measured at half the height of the main maximum and expressed as degrees of angle in the angular measurement of the glancing angle (half dispersion angle). On account of the solvent residues still initially contained in the polycarbonate, the measurement of the interference width is more reliable than that oi the crystalline fraction.

1 The density was determined by the suspension method in untensioned water.

a The filament uniformity was determined with an Ustcr instrument as a percentage mass fluctuation.

3 Example 1 den 80 Strength g./den 3.2

Elongation at break percent 28 Filament uniformity percent mass fluctuations 25 X-ray interference width degrees 2.5

Example 2 A polycarbonate of the intrinsic viscosity [1 1:085, produced from di-(4-hydroxyphenyl)-2,2-propane and phosgene, is dissolved in methylene chloride to form a 22% solution, forced through a filter press and supplied to a mixing member. A mixture of diethyleneglycol monoethylether and methylene chloride is also injected into this mixing member in such a ratio and in such a quantity that, on leaving the mixing member, there is obtained a 17% polycarbonate solution with a diethyleneglycol monoethylether content of 28%, based on the polycarbonate,

The solution, thus thoroughly mixed with the added component, is immediately forced through a 25-aperture spinneret with an aperture diameter of 0.09 mm. into a heated shaft, which is blown with heated air at the spinneret. The filaments are drawn off over roller systems and wound at a speed of 150 m./min. The filaments stretched above the ET in the ratio 1:4.8 have the following properties:

The procedure of Example 2 is followed, but a mixture of methylglycol acetate with methylene chloride is injected into the mixing member in such a ratio and in such a quantity that the result is a 17.5% polycarbonate solution with a methylglycol acetate content of 42%, based on polycarbonate. The filaments obtained after the stretching efiected in the ratio 1:5 at a temperature above the ET have the following properties:

Titre den 80 Tensile strength g./den 3.15 Elongation at break percent 27 Filament uniformity do 3.5 X-ray interference width as standard for the crystallinity "degrees" 1.32 Density 1.2140

Stability in trichloroethylene Stable Example 4 The polycarbonate solution produced according to Example 3 with an addition of methylglycol acetate is cast on a drum to form a film and is dried for 5 minutes in a stream of air at a temperature of 145 C. After the film thus produced has been stretched, it has a strength of 2 8 l g./mm. and an elongation of 26%. The X-ray interference width is l.4 with a density of 1.2210.

We claim:

1. A composition suitable for use as a spinning solution comprising at 13 to 25% by weight methylene chloride solution of a linear polycarbonate having included therein a compound of the formula:

wherein R is lower alkyl, 11 is an integer from 1 to 10 and X is a member of the group consisting of hydrogen, lower alkyl and lower alkanoyl, the amount of included compound of said formula being from 10-100% by weight, calculated on the weight of dissolved polycarbonate.

2. The composition of claim 1 wherein the compound of said formula is selected from the group consisting of diethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate and triethylene glycol dimethyl ether.

3. The composition of claim 1 wherein the compound of said formula is included in an amount of from 25 to 50% by weight, calculated on the weight of dissolved polycarbonate.

4. The composition of claim 1 wherein said composition is for spinning fibers, the concentration of the methylene chloride-polycarbonate solution is between 14 and 23% by weight and said compound of said formula is present in an amount of from 25 to by weight, calculated on the weight of dissolved polycarbonate.

5. In the process of producing shaped articles from a linear polycarbonate spinning solution, the improvement which comprises employing a 13 to 25 by weight methylene chloride solution of a linear polycarbonate having included therein a compound of the formula:

wherein R is lower alkyl, n is an integer from 1 to 10 and X is a member selected from the group consisting of hydrogen, lower alkyl and lower alkanoyl, the amount of included compound of said formula being from 10-100% by weight, calculated on the weight of dissolved polycarbonate.

References Cited UNITED STATES PATENTS 3,112,292 11/1963 Bottenbruch et a1. 260-77.5

MORRIS LIEBMAN, Primary Examiner.

J. E. CALLAGHAN, Assistant Examiner. 

